INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
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2021
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IF 3.871
Wenqiang Wang,Fang Peng,Hao Liang,Shixue Guan,Wenjia Liang,Lu Zhang,Mengyang Huang,Yue Tang,Duanwei He
As a highly controversial candidate superhard material, tungsten tetraboride (WB 4 ) has attracted widespread attention due to its desirable mechanical properties . Here, single phase WB 4 ceramics and WB 4 -based materials containing tantalum (Ta) have been successfully synthesized by a high-pressure reaction at 5.0 GPa and 1400 °C - 3000 °C. We systematically investigated the effect of processing temperature on the phase stability of WB 4 and doping with different amounts of Ta on mechanical properties and thermal stability. The results confirm that increasing treatment temperature is beneficial to the synthesis of the WB 4 phase, and high pressure can effectively inhibit the decomposition of WB 4 . Additionally, the hardness value of the WB 4 -based ceramic is found to decrease with the increase of the doped tantalum content. However, the hardness of WB 4 is less than W 0.9 Ta 0.1 B 4 (10 at. % Ta), indicating that a small amount of Ta doping is positive for the mechanical properties of WB 4 . The results show that the W 0.9 Ta 0.1 B 4 ceramic synthesized at a temperature of 2800 °C and 5.0 GPa has excellent overall properties. Its Vickers hardness is 42 GPa (0.49 N), and its oxidation resistance temperature is 542 °C, which is much higher than the hardness and thermal stability of tungsten carbide (WC). This work can provide practical guide for the design of new transition metal boride superhard materials, and point out the visual direction for exploring the next generation of superhard materials.
研究领域:
材料科学
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固体力学
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产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
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2019
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IF 10.159
Yan Jie Wang,Xin Ning Zhang,Yihu Song,Yiping Zhao,Li Chen,Fengmei Su,Liangbin Li,Zi Liang Wu,Qiang Zheng
Design of tough hydrogels has made great progress in the past two decades. However, the synthetic tough gels are usually much softer than some biotissues (e.g., skins with modulus up to 100 MPa). Here we report a new class of ultrastiff and tough supramolecular hydrogels facilely prepared by copolymerization of methacrylic acid and methacrylamide. The gels with water content of approximately 50–70 wt % possessed remarkable mechanical properties, with Young’s modulus of 2.3–217.3 MPa, tensile breaking stress of 1.2–8.3 MPa, breaking strain of 200–620%, and tearing fracture energy of 2.9–23.5 kJ/m2, superior to most existing hydrogels, especially in terms of modulus. Typical yielding and crazing were observed in the gel under tensile loading, indicating the forced elastic deformation of these hydrogels in a glassy state, as confirmed by dynamic mechanical analysis. The ultrahigh stiffness was attributed to the dense cross-linking and reduced segmental mobility caused by the robust intra- and interchain hydrogen bonds. Because of the dynamic nature of noncovalent bonds, these supramolecular gels also showed rate-dependent mechanical performances along with good shape memory and recyclability. This strategy should be applicable for other systems toward robust mechanical properties, versatile functionalities, and promising applications of hydrogel materials as structural elements.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2023
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IF 6.2
Pengbo Zhao,Jinpeng Zhu,Mingliang Li,Gang Shao,Hailong Wang,Jilin He
High-entropy monoborides (HEMBs) are promising materials for use in cutting tools and wear-resistant coatings owing to their super hardness. Because of the scarcity of reports on powder synthesis , extensive application of HEMBs is limited. To address this problem, a molten-salt-assisted strategy for synthesising HEMB powders is proposed herein. High-entropy (V 0.2 Cr 0.2 Mo 0.2 W 0.2 Ni 0.2 )B powders with CrB-type orthogonal crystal structures were successfully synthesised at 1500 °C and examined by using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy . Subsequently, the mechanism of powder synthesis using molten salt and the advantages of powders prepared by employing molten salt for the densification and hardness enhancement of ceramics were comprehensively evaluated. The (V 0.2 Cr 0.2 Mo 0.2 W 0.2 Ni 0.2 )B powders were densified by applying spark plasma sintering to study the microstructural evolution of bulk ceramics with a super hardness of 42.19 ± 2.66 GPa. This work has expanded the family of superhard HEMBs and provides a strong support for the further application of HEMBs.
研究领域:
材料科学
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陶瓷工程
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纳米技术
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产品关联
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
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2025
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IF 3.4
Yunxia Han,Chao Gu,Jian Chen,Guozhu Song,Yusheng Zhao,Mingyu Gong,Shanmin Wang
Incorporation of defects into covalent solids (e.g., diamond) can greatly alter their electronic and structural properties for creating optically active color centers, which also leads to largely adjusted mechanical properties. As an electronic equivalent to diamond, cubic boron nitride (cBN) with superhardness is often formed with crystalline imperfections. However, the defect dependences of color centers and mechanical properties in cBN have been rarely explored due to the difficulties in synthesizing defective crystals with controllable defects, which have largely limited its functionality. In this work, we present a systematic study of various defective cBN crystals prepared from different catalyst systems under high pressure with a focus on the optical and mechanical properties. A number of distinct color centers have been identified for emitting luminescence across a broad spectrum of lights, ranging from infrared to ultraviolet. Because of the defects, the hardness of cBN crystals can also be largely tuned in a wide range of 43–63 GPa. These findings offer important foundations for rationally tailoring the optical and mechanical properties of diamond-like covalent solids by defect chemistry.
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产品关联
DOI
高影响因子
Functional Diamond
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2022
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IF 0
Zhiqiang Hou,Haikuo Wang,Yao Tang,Jiakun Wu,Chao Wang,Zhicai Zhang,Xiaoping Ouyang
Carbon, the fourth most abundant element in the Universe, possesses numerous allotropes with diverse bonding character (sp1-, sp2- and sp3-hybridized bonds) and structural motif of the constituting atoms. In particular, the carbon materials with a fully or nearly 100% sp3-hybridized strong C-C bonds often lead to excellent mechanical properties, chemical stability, thermal and optical properties, such as crystalline diamond and diamond-like amorphous carbon (DLC). In this review, we systematically summarize the synthesis, microstructure, mechanical properties, thermal and optical properties of ultrahard carbon materials with current experimental results on nano-polycrystalline diamond (NPD), nanotwinned diamond (NTD), micro-grained polycrystalline diamond (MPD), and amorphous diamond/carbon. In addition, we discuss the difference of spectra of XRD, Raman and EELS between various nanocrystalline diamond powder and ultrahard carbon materials. Finally, we provide our insights into the future development and applications in the research of ultrahard carbon bulk materials by high-pressure and high-temperature techniques according to the current advantages, limitations and challenges in the experiment.
研究领域:
材料科学
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凝聚态物理
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光谱学
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DOI
CRYSTAL GROWTH & DESIGN
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2020
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IF 4.089
Yunxia Han,Duanwei He,Dejiang Ma,Qiming Wang,Yusheng Zhao,Shanmin Wang,Mingquan Jiang,Xin Li,Jiawei Zhang
We report high-pressure synthesis of single-crystal boron suboxide (B6O), one of the superhard materials, using a reaction route between B and H3BO3 at 3–5.5 GPa and 600–2200 °C. At optimized pressure and temperature conditions of 5.5 GPa and 2100 °C, large B6O single crystals can be obtained with a crystallite size of more than 2 mm. Boric acid (H3BO3) was used as a starting material because it is easily decomposed into B2O3 and H2O at a lower temperature. The B2O3 produced by the decomposition should have a small particle size and thus have high reactivity, and the reaction byproduct H2O provides a good hydrostatic environment for the growth of B6O. Therefore, it is easier to synthesize and grow B6O by using a B-H3BO3 system as reaction raw materials. This work discussed the B6O growth mechanism in detail. In addition, photoluminescence experiments and first-principles calculations show that B6O is a direct band gap semiconductor material with good orange-red emission characteristics (the band gap is 1.83 eV). The results of this study indicate a method to grow large B6O single crystals that have great potential use in industrial applications.
研究领域:
材料科学
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晶体生长
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半导体物理
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产品关联
DOI
高影响因子
ACS Nano
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2022
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IF 18.027
Xuefang Lu,Richeng Lin,Yuqiang Li,Ying Ding,Yali Liang,Lemin Jia,Zhuogeng Lin,Siqi Zhu,Feng Huang,Wei Zheng
An urgent demand for electronic and optoelectronic devices able to work in extreme environments promotes a series of research studies on semiconductor materials. Cubic boron phosphide (BP) as a semiconductor material with excellent characteristics shows great application potential. However, since the synthesis conditions required are difficult to achieve and the growth mechanism of BP is still unclear, there are few reports on the basic properties of BP and pure isotope BP, resulting in a narrow understanding of their special physical properties. Here, we successfully obtained highly pure isotopic 10BP crystals by a vapor–liquid–solid (VLS) method unconventionally designed, which successfully overcomes the thermodynamic conflict between the high melting point of the boron element and low sublimation temperature of the phosphorus element. The 10BP achieved owns an aspect ratio as high as 104 and a hardness up to 41 GPa. Besides, as an indirect bandgap semiconductor, it has ultrawide red emission spectra, a p-type conductivity with extremely low resistivity, and excellent photoelectronic and piezoelectric characteristics. Furthermore, compared with other superhard semiconductors like cubic BN and diamond, 10BP has an obvious advantage of lower growth temperature (1200 °C). All these characteristics confirm the prospects owned by 10BP in its applications to the field of high-conductivity, optoelectronic, strain-sensing, and superhard semiconductors.
研究领域:
材料科学
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半导体物理
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光电技术
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纳米技术
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机械工程
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）